Certain cable modem termination systems (CMTSs) currently support optimized use of downstream (“DS”) and upstream (“US”) channel resources through the cable load balancing feature. Typically, with US load balancing, the system will try to balance the load among a number of pre-assigned US channels for a given radiofrequency (“RF”) domain. If a combination of US and DS load balancing is in use, then all the RF domains that are part of the same load balance group must be available on a shared RF plant. Currently, the number of US channels assigned to an RF domain is statically configured, either by keeping the default value (typically, four channels per domain) or by assigning a variable number of US channels per domain by configuring virtual interfaces.
Through effective traffic engineering and capacity planning, multiple cable-system operators (“MSOs”) might be able to predict future subscriber growth and the corresponding increase in traffic rates per fiber node, and increase accordingly the upstream channels per RF domain in order to make sure that the use of available resources is optimized. However, it takes considerable effort to realize such capacity planning, and sometimes the unforeseen growth patterns could happen for different market segments. As a result, the node split or cable re-arrangement on the RF side may be required to accommodate demand for higher bandwidths.
Further, different segments might exhibit different traffic usage patterns at different times of the day or even during different days of the week. For example, if, for a particular RF domain, the number of business subscribers is much higher than the number of residential subscribers, it may be that the traffic rates during business hours would be much higher than during non-business hours. Consequently, the optimum number of US channels required for this RF domain during daytime hours might be four, while during nighttime hours it might be two. Conversely, if there were another RF domain with a significantly higher number of residential subscribers than business subscribers, it may be that the traffic rate during evening hours would be much higher than that during daytime hours. The optimum number of US channels required for this RF domain during daytime hours might be two, while during nighttime hours it might be four. For better utilization of US channels, it would be desirable if there were an automated mechanism available to dynamically allocate upstream channel resources between RF domains depending on their current traffic loads.
In another scenario, a short term increase in bandwidth requirements on one or more fiber nodes serving one or more geographic neighborhoods might be desirable. An example of such a scenario might be a televised contest wherein viewers are invited to call in and vote for their favorite contestant. It is very likely that there will be significantly high volumes of calls from the neighborhoods in which the contestants live, as their neighbors all call in at once to vote for their local candidate. One way to address this temporary bandwidth requirement would be to add another channel, which may require cabling changes as well as manual configuration changes. Also, such additional resources would be held up indefinitely for this temporary condition. And, afterward, more manual intervention, including cabling changes, may be required to remove the additional channel. If an automated mechanism were in place to add an upstream channel on demand to an RF domain, this temporary increase in bandwidth requirement could be accomplished without such cabling changes and configuration modifications.